Analog Devices Inc. LTC1272-3ACSW#PBF

Overview

LTC1272-3ACSW#PBF from Analog Devices (formerly Linear Technology) is a 12-bit, 3 µs successive approximation ADC with integrated sample-and-hold and on-chip 2.42 V precision reference. It operates from a single 5 V supply, delivers up to 250 kHz sampling rate, and maintains ±0.5 LSB integral linearity over 0°C to 70°C - enabling high-speed data acquisition in industrial control and DSP systems.

For engineers reviewing the LTC1272-3ACSW#PBF datasheet, LTC1272-3ACSW#PBF pinout, LTC1272-3ACSW#PBF application, or LTC1272-3ACSW#PBF equivalent, key selection considerations include its AD7572-pin-compatible footprint, single-supply operation eliminating negative rails, 1 µs minimum inter-conversion delay, and dual-mode 8-bit/12-bit parallel output for 8-bit and 16-bit microprocessor interfacing.

Technical Context

The LTC1272-3ACSW#PBF implements a switched-capacitor SAR architecture with internal 12-bit capacitive DAC and comparator-based bit decision logic synchronized to CLK IN edges. Conversion begins on CS/RD falling edge and completes in exactly 13 clock cycles at 4 MHz, with aperture jitter <50 ps and sample-and-hold acquisition time ≤1 µs.

Its analog front-end uses a 300 Ω / 2.7 kΩ input divider to support 0 V to 5 V unipolar input range from 4.75 V to 5.25 V supply, while the curvature-corrected bandgap reference provides 2.42 V ±1% output with 25 ppm/°C tempco and 2 LSB/mA load regulation - directly driving the DAC and available at Pin 2 for external decoupling.

Key Specifications

Pinout & Package

24-lead plastic SO wide (SW) package, 0.300" body width, gull-wing leads, RoHS-compliant lead-free finish (PBF). Thermal resistance θ_JA = 130°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit sampling ADC applications.

Compared with AD7572KNZ, LTC1272-3ACSW#PBF delivers 2.7× faster conversion and eliminates negative supply; versus MAX11200EEE+, it offers 25× higher throughput but trades resolution for speed - making it optimal for real-time sampled-data control rather than static measurement.

Availability

LTC1272-3ACSW#PBF is available at Aetrix Electronics and suitable for industrial process monitoring, digital signal processing front-ends, and multiplexed data acquisition systems requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.

Supply support for LTC1272-3ACSW#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC1272 family was developed by Linear Technology (acquired by ADI in 2017) to deliver pin-compatible, higher-speed replacements for industry-standard 12-bit SAR ADCs - targeting data acquisition, test equipment, and real-time control where single-supply operation and minimal external components are critical.

FAQ

What is the maximum sampling rate supported by the LTC1272-3ACSW#PBF?

The LTC1272-3ACSW#PBF supports a maximum sustained sampling rate of 250 kHz, achieved using its internal 4 MHz clock and 3 µs conversion time. This rate is validated under conditions of 0 V to 5 V input, VDD = 5 V, and proper decoupling - and is limited by the 1 µs minimum delay between conversions (t11) specified in the datasheet.

Can the LTC1272-3ACSW#PBF replace an AD7572 in an existing PCB layout?

Yes, the LTC1272-3ACSW#PBF is designed as a drop-in replacement for the AD7572 in 24-pin DIP or SO packages. Key adaptations required are reversing the polarity of the VREF bypass capacitor (due to +2.42 V vs –5.25 V reference) and leaving Pin 23 (NC) unconnected - no PCB trace modifications are needed for signal or power routing.

How does the HBEN pin affect data output formatting on the LTC1272-3ACSW#PBF?

When HBEN = LOW, the LTC1272-3ACSW#PBF outputs the full 12-bit result (DB11–DB0) across D11–D0/8 simultaneously. When HBEN = HIGH, it multiplexes: D11–D8 carry DB11–DB8 (upper byte), and D3/11–D0/8 carry DB11–DB8 again - enabling two sequential 8-bit reads to reconstruct the 12-bit word on 8-bit microcontrollers.

What is the purpose of the NC pin (Pin 23) on the LTC1272-3ACSW#PBF?

Pin 23 on the LTC1272-3ACSW#PBF is Not Connected internally and replaces the AD7572's –15 V supply pin. It is electrically isolated and may be left floating or tied to ground - its presence maintains mechanical compatibility with AD7572 sockets while eliminating the need for negative supply generation in new designs using the LTC1272-3ACSW#PBF.

Does the LTC1272-3ACSW#PBF require an external clock source?

No, the LTC1272-3ACSW#PBF supports both external clock input at CLK IN (Pin 17) and internal crystal oscillator configuration using a 4 MHz crystal between CLK IN and CLK OUT (Pins 17 and 18). The internal oscillator eliminates timing component count, while external clocking allows synchronization to system timing domains - both modes are fully supported without hardware change.